Single-Center Study Shows Gender Differences for Elective EVAR

April 20, 2012—According to a single-center study published in the Journal of Vascular Surgery, mortality is significantly greater for women undergoing elective endovascular repair (EVAR) for abdominal aortic aneurysms (AAA) than for men (2012;55:906–913). The study also showed that colon ischemia, native arterial rupture, and type 1 endoleaks are more frequent in women than in men. Elective EVAR benefits men more than women, concluded Manish Mehta, MD, et al, from the Vascular Group at the Albany Medical Center in Albany, New York.

As background to the study, the investigators noted that although EVAR has clearly reduced early and midterm morbidity and mortality for patients with large AAAs, most EVAR patients are male. Furthermore, it is unclear whether there has been any reduction in elective morbidity for females or what the extent of that reduction has been. Women are also known to have a lower chance of surviving elective open AAA repair but the reasons for this are not clear.

In this study the investigators prospectively analyzed outcomes for elective EVAR in women at their center and compared results with those for elective open surgery and emergent open and endovascular repair.

As detailed in the Journal of Vascular Surgery, all patients undergoing elective and emergency AAA repair from 2002 to 2009 were prospectively entered into a database and their demographic details, including gender, were tabulated. Outcome measures were operative blood loss, incidence of type 1 endoleaks, length of in-hospital stay, postoperative complications, 30-day all-cause mortality, and secondary interventions during the follow-up period. Statistical analysis was performed using Fisher's exact test and Student's t-test. A multivariate analysis was also performed.

From 2002 to 2009, there were 2,631 total EVAR and open repairs of AAAs performed in the investigators' center (1,698 EVAR and 933 open). The study population was composed of 1,995 men (76%) and 636 women (24%). There were 1,592 elective EVARs (1,248 male, 344 female) and 106 emergency EVARs (73 male, 33 female). Elective open repair was performed in 788 patients (579 male, 209 female) and emergency open repair in 149 patients (73 male, 76 female).

The investigators reported that elective EVAR for women resulted in significantly greater mortality rates than men (3.2% vs 0.96%; P < .005). There was a greater incidence of intraoperative aortic neck or iliac artery rupture (4.1% vs 1.2%; P = .002) and use of Palmaz stents (Cordis Corporation, Bridgewater, NJ) for type 1 endoleaks (16.1% vs 8%; P = .0009). Mean blood loss was also greater in women (327 mL vs 275 mL; P = .038).

The investigators also found that perioperative complications were more frequent in women: leg ischemia (3.5% vs 0.6%; P = .003) and colon ischemia requiring colectomy (0.9% vs 0.2%; P = .009). Mean hospital stay was also longer for women than men (3.7 days vs 2.2 days; P = .0001).

In contrast, the investigators reported that there were no gender differences for any of these outcome measures for elective open repair, emergency open surgery, or EVAR. There was no significant difference in death rates between EVAR and open repair in women (3.2% vs 5.7%). In men, the 30-day mortality was 0.96% for elective EVAR and 4.7% for elective open surgery. Following logistic regression, the investigators stated that female sex remains a significant risk even when the effects of aneurysm size and age are considered (odds ratio, 3.4; P < .01).